<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/x86/kernel/tboot.c, branch v5.6</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>remove ioremap_nocache and devm_ioremap_nocache</title>
<updated>2020-01-06T08:45:59+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2020-01-06T08:43:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4bdc0d676a643140bdf17dbf7eafedee3d496a3c'/>
<id>4bdc0d676a643140bdf17dbf7eafedee3d496a3c</id>
<content type='text'>
ioremap has provided non-cached semantics by default since the Linux 2.6
days, so remove the additional ioremap_nocache interface.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
ioremap has provided non-cached semantics by default since the Linux 2.6
days, so remove the additional ioremap_nocache interface.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86: Use pr_warn instead of pr_warning</title>
<updated>2019-10-18T13:00:18+00:00</updated>
<author>
<name>Kefeng Wang</name>
<email>wangkefeng.wang@huawei.com</email>
</author>
<published>2019-10-18T03:18:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8d3bcc441e6cddbb5fe49b59f7766f01f1e2493b'/>
<id>8d3bcc441e6cddbb5fe49b59f7766f01f1e2493b</id>
<content type='text'>
As said in commit f2c2cbcc35d4 ("powerpc: Use pr_warn instead of
pr_warning"), removing pr_warning so all logging messages use a
consistent &lt;prefix&gt;_warn style. Let's do it.

Link: http://lkml.kernel.org/r/20191018031850.48498-7-wangkefeng.wang@huawei.com
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Robert Richter &lt;rric@kernel.org&gt;
Cc: Darren Hart &lt;dvhart@infradead.org&gt;
Cc: Andy Shevchenko &lt;andy@infradead.org&gt;
Signed-off-by: Kefeng Wang &lt;wangkefeng.wang@huawei.com&gt;
Reviewed-by: Sergey Senozhatsky &lt;sergey.senozhatsky@gmail.com&gt;
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As said in commit f2c2cbcc35d4 ("powerpc: Use pr_warn instead of
pr_warning"), removing pr_warning so all logging messages use a
consistent &lt;prefix&gt;_warn style. Let's do it.

Link: http://lkml.kernel.org/r/20191018031850.48498-7-wangkefeng.wang@huawei.com
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Robert Richter &lt;rric@kernel.org&gt;
Cc: Darren Hart &lt;dvhart@infradead.org&gt;
Cc: Andy Shevchenko &lt;andy@infradead.org&gt;
Signed-off-by: Kefeng Wang &lt;wangkefeng.wang@huawei.com&gt;
Reviewed-by: Sergey Senozhatsky &lt;sergey.senozhatsky@gmail.com&gt;
Signed-off-by: Petr Mladek &lt;pmladek@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 335</title>
<updated>2019-06-05T15:37:06+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-05-29T23:57:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a61127c2130236168321cc76c5a58e15c00ad154'/>
<id>a61127c2130236168321cc76c5a58e15c00ad154</id>
<content type='text'>
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not write to the free
  software foundation inc 51 franklin st fifth floor boston ma 02110
  1301 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 111 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Alexios Zavras &lt;alexios.zavras@intel.com&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.567572064@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not write to the free
  software foundation inc 51 franklin st fifth floor boston ma 02110
  1301 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 111 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Alexios Zavras &lt;alexios.zavras@intel.com&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000436.567572064@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>iommu/vtd: Cleanup dma_remapping.h header</title>
<updated>2018-11-12T13:22:56+00:00</updated>
<author>
<name>Lu Baolu</name>
<email>baolu.lu@linux.intel.com</email>
</author>
<published>2018-11-12T06:40:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=daedaa33d9c578220b311fbad3748d3ecd5a8f66'/>
<id>daedaa33d9c578220b311fbad3748d3ecd5a8f66</id>
<content type='text'>
Commit e61d98d8dad00 ("x64, x2apic/intr-remap: Intel vt-d, IOMMU
code reorganization") moved dma_remapping.h from drivers/pci/ to
current place. It is entirely VT-d specific, but uses a generic
name. This merges dma_remapping.h with include/linux/intel-iommu.h
and removes dma_remapping.h as the result.

Cc: Ashok Raj &lt;ashok.raj@intel.com&gt;
Cc: Jacob Pan &lt;jacob.jun.pan@linux.intel.com&gt;
Cc: Sohil Mehta &lt;sohil.mehta@intel.com&gt;
Suggested-by: Christoph Hellwig &lt;hch@infradead.org&gt;
Signed-off-by: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Liu, Yi L &lt;yi.l.liu@intel.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit e61d98d8dad00 ("x64, x2apic/intr-remap: Intel vt-d, IOMMU
code reorganization") moved dma_remapping.h from drivers/pci/ to
current place. It is entirely VT-d specific, but uses a generic
name. This merges dma_remapping.h with include/linux/intel-iommu.h
and removes dma_remapping.h as the result.

Cc: Ashok Raj &lt;ashok.raj@intel.com&gt;
Cc: Jacob Pan &lt;jacob.jun.pan@linux.intel.com&gt;
Cc: Sohil Mehta &lt;sohil.mehta@intel.com&gt;
Suggested-by: Christoph Hellwig &lt;hch@infradead.org&gt;
Signed-off-by: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Liu, Yi L &lt;yi.l.liu@intel.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/pti: Make unpoison of pgd for trusted boot work for real</title>
<updated>2018-01-11T22:36:59+00:00</updated>
<author>
<name>Dave Hansen</name>
<email>dave.hansen@linux.intel.com</email>
</author>
<published>2018-01-10T22:49:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=445b69e3b75e42362a5bdc13c8b8f61599e2228a'/>
<id>445b69e3b75e42362a5bdc13c8b8f61599e2228a</id>
<content type='text'>
The inital fix for trusted boot and PTI potentially misses the pgd clearing
if pud_alloc() sets a PGD.  It probably works in *practice* because for two
adjacent calls to map_tboot_page() that share a PGD entry, the first will
clear NX, *then* allocate and set the PGD (without NX clear).  The second
call will *not* allocate but will clear the NX bit.

Defer the NX clearing to a point after it is known that all top-level
allocations have occurred.  Add a comment to clarify why.

[ tglx: Massaged changelog ]

Fixes: 262b6b30087 ("x86/tboot: Unbreak tboot with PTI enabled")
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Jon Masters &lt;jcm@redhat.com&gt;
Cc: "Tim Chen" &lt;tim.c.chen@linux.intel.com&gt;
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: peterz@infradead.org
Cc: ning.sun@intel.com
Cc: tboot-devel@lists.sourceforge.net
Cc: andi@firstfloor.org
Cc: luto@kernel.org
Cc: law@redhat.com
Cc: pbonzini@redhat.com
Cc: torvalds@linux-foundation.org
Cc: gregkh@linux-foundation.org
Cc: dwmw@amazon.co.uk
Cc: nickc@redhat.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180110224939.2695CD47@viggo.jf.intel.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The inital fix for trusted boot and PTI potentially misses the pgd clearing
if pud_alloc() sets a PGD.  It probably works in *practice* because for two
adjacent calls to map_tboot_page() that share a PGD entry, the first will
clear NX, *then* allocate and set the PGD (without NX clear).  The second
call will *not* allocate but will clear the NX bit.

Defer the NX clearing to a point after it is known that all top-level
allocations have occurred.  Add a comment to clarify why.

[ tglx: Massaged changelog ]

Fixes: 262b6b30087 ("x86/tboot: Unbreak tboot with PTI enabled")
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Cc: Jon Masters &lt;jcm@redhat.com&gt;
Cc: "Tim Chen" &lt;tim.c.chen@linux.intel.com&gt;
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: peterz@infradead.org
Cc: ning.sun@intel.com
Cc: tboot-devel@lists.sourceforge.net
Cc: andi@firstfloor.org
Cc: luto@kernel.org
Cc: law@redhat.com
Cc: pbonzini@redhat.com
Cc: torvalds@linux-foundation.org
Cc: gregkh@linux-foundation.org
Cc: dwmw@amazon.co.uk
Cc: nickc@redhat.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180110224939.2695CD47@viggo.jf.intel.com
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/tboot: Unbreak tboot with PTI enabled</title>
<updated>2018-01-08T16:29:18+00:00</updated>
<author>
<name>Dave Hansen</name>
<email>dave.hansen@linux.intel.com</email>
</author>
<published>2018-01-06T17:41:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=262b6b30087246abf09d6275eb0c0dc421bcbe38'/>
<id>262b6b30087246abf09d6275eb0c0dc421bcbe38</id>
<content type='text'>
This is another case similar to what EFI does: create a new set of
page tables, map some code at a low address, and jump to it.  PTI
mistakes this low address for userspace and mistakenly marks it
non-executable in an effort to make it unusable for userspace.

Undo the poison to allow execution.

Fixes: 385ce0ea4c07 ("x86/mm/pti: Add Kconfig")
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Signed-off-by: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Alan Cox &lt;gnomes@lxorguk.ukuu.org.uk&gt;
Cc: Tim Chen &lt;tim.c.chen@linux.intel.com&gt;
Cc: Jon Masters &lt;jcm@redhat.com&gt;
Cc: Dave Hansen &lt;dave.hansen@intel.com&gt;
Cc: Andi Kleen &lt;andi@firstfloor.org&gt;
Cc: Jeff Law &lt;law@redhat.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linux-foundation.org&gt;
Cc: David" &lt;dwmw@amazon.co.uk&gt;
Cc: Nick Clifton &lt;nickc@redhat.com&gt;
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180108102805.GK25546@redhat.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is another case similar to what EFI does: create a new set of
page tables, map some code at a low address, and jump to it.  PTI
mistakes this low address for userspace and mistakenly marks it
non-executable in an effort to make it unusable for userspace.

Undo the poison to allow execution.

Fixes: 385ce0ea4c07 ("x86/mm/pti: Add Kconfig")
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Signed-off-by: Andrea Arcangeli &lt;aarcange@redhat.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Alan Cox &lt;gnomes@lxorguk.ukuu.org.uk&gt;
Cc: Tim Chen &lt;tim.c.chen@linux.intel.com&gt;
Cc: Jon Masters &lt;jcm@redhat.com&gt;
Cc: Dave Hansen &lt;dave.hansen@intel.com&gt;
Cc: Andi Kleen &lt;andi@firstfloor.org&gt;
Cc: Jeff Law &lt;law@redhat.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linux-foundation.org&gt;
Cc: David" &lt;dwmw@amazon.co.uk&gt;
Cc: Nick Clifton &lt;nickc@redhat.com&gt;
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180108102805.GK25546@redhat.com
</pre>
</div>
</content>
</entry>
<entry>
<title>iommu/vt-d: Correctly disable Intel IOMMU force on</title>
<updated>2017-06-15T14:41:10+00:00</updated>
<author>
<name>Shaohua Li</name>
<email>shli@fb.com</email>
</author>
<published>2017-06-08T18:27:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7304e8f28bb2f3cb2baf37c1bb2caa0f54ca4e43'/>
<id>7304e8f28bb2f3cb2baf37c1bb2caa0f54ca4e43</id>
<content type='text'>
I made a mistake in commit bfd20f1. We should skip the force on with the
option enabled instead of vice versa. Not sure why this passed our
performance test, sorry.

Fixes: bfd20f1cc850 ('x86, iommu/vt-d: Add an option to disable Intel IOMMU force on')
Signed-off-by: Shaohua Li &lt;shli@fb.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
I made a mistake in commit bfd20f1. We should skip the force on with the
option enabled instead of vice versa. Not sure why this passed our
performance test, sorry.

Fixes: bfd20f1cc850 ('x86, iommu/vt-d: Add an option to disable Intel IOMMU force on')
Signed-off-by: Shaohua Li &lt;shli@fb.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'iommu-updates-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu</title>
<updated>2017-05-09T22:15:47+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-05-09T22:15:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=28b47809b2171a6cfbab839936b24280639c9f85'/>
<id>28b47809b2171a6cfbab839936b24280639c9f85</id>
<content type='text'>
Pull IOMMU updates from Joerg Roedel:

 - code optimizations for the Intel VT-d driver

 - ability to switch off a previously enabled Intel IOMMU

 - support for 'struct iommu_device' for OMAP, Rockchip and Mediatek
   IOMMUs

 - header optimizations for IOMMU core code headers and a few fixes that
   became necessary in other parts of the kernel because of that

 - ACPI/IORT updates and fixes

 - Exynos IOMMU optimizations

 - updates for the IOMMU dma-api code to bring it closer to use per-cpu
   iova caches

 - new command-line option to set default domain type allocated by the
   iommu core code

 - another command line option to allow the Intel IOMMU switched off in
   a tboot environment

 - ARM/SMMU: TLB sync optimisations for SMMUv2, Support for using an
   IDENTITY domain in conjunction with DMA ops, Support for SMR masking,
   Support for 16-bit ASIDs (was previously broken)

 - various other small fixes and improvements

* tag 'iommu-updates-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (63 commits)
  soc/qbman: Move dma-mapping.h include to qman_priv.h
  soc/qbman: Fix implicit header dependency now causing build fails
  iommu: Remove trace-events include from iommu.h
  iommu: Remove pci.h include from trace/events/iommu.h
  arm: dma-mapping: Don't override dma_ops in arch_setup_dma_ops()
  ACPI/IORT: Fix CONFIG_IOMMU_API dependency
  iommu/vt-d: Don't print the failure message when booting non-kdump kernel
  iommu: Move report_iommu_fault() to iommu.c
  iommu: Include device.h in iommu.h
  x86, iommu/vt-d: Add an option to disable Intel IOMMU force on
  iommu/arm-smmu: Return IOVA in iova_to_phys when SMMU is bypassed
  iommu/arm-smmu: Correct sid to mask
  iommu/amd: Fix incorrect error handling in amd_iommu_bind_pasid()
  iommu: Make iommu_bus_notifier return NOTIFY_DONE rather than error code
  omap3isp: Remove iommu_group related code
  iommu/omap: Add iommu-group support
  iommu/omap: Make use of 'struct iommu_device'
  iommu/omap: Store iommu_dev pointer in arch_data
  iommu/omap: Move data structures to omap-iommu.h
  iommu/omap: Drop legacy-style device support
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull IOMMU updates from Joerg Roedel:

 - code optimizations for the Intel VT-d driver

 - ability to switch off a previously enabled Intel IOMMU

 - support for 'struct iommu_device' for OMAP, Rockchip and Mediatek
   IOMMUs

 - header optimizations for IOMMU core code headers and a few fixes that
   became necessary in other parts of the kernel because of that

 - ACPI/IORT updates and fixes

 - Exynos IOMMU optimizations

 - updates for the IOMMU dma-api code to bring it closer to use per-cpu
   iova caches

 - new command-line option to set default domain type allocated by the
   iommu core code

 - another command line option to allow the Intel IOMMU switched off in
   a tboot environment

 - ARM/SMMU: TLB sync optimisations for SMMUv2, Support for using an
   IDENTITY domain in conjunction with DMA ops, Support for SMR masking,
   Support for 16-bit ASIDs (was previously broken)

 - various other small fixes and improvements

* tag 'iommu-updates-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (63 commits)
  soc/qbman: Move dma-mapping.h include to qman_priv.h
  soc/qbman: Fix implicit header dependency now causing build fails
  iommu: Remove trace-events include from iommu.h
  iommu: Remove pci.h include from trace/events/iommu.h
  arm: dma-mapping: Don't override dma_ops in arch_setup_dma_ops()
  ACPI/IORT: Fix CONFIG_IOMMU_API dependency
  iommu/vt-d: Don't print the failure message when booting non-kdump kernel
  iommu: Move report_iommu_fault() to iommu.c
  iommu: Include device.h in iommu.h
  x86, iommu/vt-d: Add an option to disable Intel IOMMU force on
  iommu/arm-smmu: Return IOVA in iova_to_phys when SMMU is bypassed
  iommu/arm-smmu: Correct sid to mask
  iommu/amd: Fix incorrect error handling in amd_iommu_bind_pasid()
  iommu: Make iommu_bus_notifier return NOTIFY_DONE rather than error code
  omap3isp: Remove iommu_group related code
  iommu/omap: Add iommu-group support
  iommu/omap: Make use of 'struct iommu_device'
  iommu/omap: Store iommu_dev pointer in arch_data
  iommu/omap: Move data structures to omap-iommu.h
  iommu/omap: Drop legacy-style device support
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>x86, iommu/vt-d: Add an option to disable Intel IOMMU force on</title>
<updated>2017-04-26T21:57:53+00:00</updated>
<author>
<name>Shaohua Li</name>
<email>shli@fb.com</email>
</author>
<published>2017-04-26T16:18:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bfd20f1cc85010d2f2d77e544da05cd8c149ba9b'/>
<id>bfd20f1cc85010d2f2d77e544da05cd8c149ba9b</id>
<content type='text'>
IOMMU harms performance signficantly when we run very fast networking
workloads. It's 40GB networking doing XDP test. Software overhead is
almost unaware, but it's the IOTLB miss (based on our analysis) which
kills the performance. We observed the same performance issue even with
software passthrough (identity mapping), only the hardware passthrough
survives. The pps with iommu (with software passthrough) is only about
~30% of that without it. This is a limitation in hardware based on our
observation, so we'd like to disable the IOMMU force on, but we do want
to use TBOOT and we can sacrifice the DMA security bought by IOMMU. I
must admit I know nothing about TBOOT, but TBOOT guys (cc-ed) think not
eabling IOMMU is totally ok.

So introduce a new boot option to disable the force on. It's kind of
silly we need to run into intel_iommu_init even without force on, but we
need to disable TBOOT PMR registers. For system without the boot option,
nothing is changed.

Signed-off-by: Shaohua Li &lt;shli@fb.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
IOMMU harms performance signficantly when we run very fast networking
workloads. It's 40GB networking doing XDP test. Software overhead is
almost unaware, but it's the IOTLB miss (based on our analysis) which
kills the performance. We observed the same performance issue even with
software passthrough (identity mapping), only the hardware passthrough
survives. The pps with iommu (with software passthrough) is only about
~30% of that without it. This is a limitation in hardware based on our
observation, so we'd like to disable the IOMMU force on, but we do want
to use TBOOT and we can sacrifice the DMA security bought by IOMMU. I
must admit I know nothing about TBOOT, but TBOOT guys (cc-ed) think not
eabling IOMMU is totally ok.

So introduce a new boot option to disable the force on. It's kind of
silly we need to run into intel_iommu_init even without force on, but we
need to disable TBOOT PMR registers. For system without the boot option,
nothing is changed.

Signed-off-by: Shaohua Li &lt;shli@fb.com&gt;
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'x86/boot' into x86/mm, to avoid conflict</title>
<updated>2017-04-11T06:56:05+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2017-04-11T06:56:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e5185a76a23b2d56fb2327ad8bd58fb1bcaa52b1'/>
<id>e5185a76a23b2d56fb2327ad8bd58fb1bcaa52b1</id>
<content type='text'>
There's a conflict between ongoing level-5 paging support and
the E820 rewrite. Since the E820 rewrite is essentially ready,
merge it into x86/mm to reduce tree conflicts.

Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There's a conflict between ongoing level-5 paging support and
the E820 rewrite. Since the E820 rewrite is essentially ready,
merge it into x86/mm to reduce tree conflicts.

Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
